Environmental monitoring wells are typically used in monitoring underground water quality, in cases where contamination is suspected. In order to obtain water samples from the well, a bailer or a pump is lowered into the well with a hoist. Typically, the hoist would be supported on a tripod positioned over the well casing. Where there is uneven ground around the well casing, one would recognize that it would be relatively difficult to position the tripod in a stable configuration while maintaining it centered above the well opening.
The present invention solves the above problem by providing a hoist that secures to the well casing and that includes means for automatic centering or aligning over the well opening.